1. Field of the Invention
The present invention relates to an electronic device and a method making use of the same for the detection of a touch trace, and more particularly, to an electronic device and a method making use of the same for the detection of a touch trace which starts beyond the touch area.
2. Description of the Prior Art
Touch sensitive input has become one of the most common human-computer interfaces today. In particular, touch panels and touch pads are now standard input devices for modern consumer electronic products. The former is widely used in smart phones e.g. Apple's iPhone and iPad, and the later is used in laptops. In other words, the consumer electronic products today come with at least one of these two input devices. In fact, more and more laptops are provided with both, for example the new Windows 8-based products.
All touch modules come with a defined touch area, which is able to receive touch events triggered by physical contacts thereon of the user body or a stylus. The touch event, when detected by the hardware of the touch module, enables an interrupt request to the operating system so that it is informed of the coordinates in the touch area where the touch event took place. When a series of multiple touch events take place, they are associated by either the firmware of the touch module, the operating system or the higher level applications to form a touch trace. In other words, a touch trace is typically defined as a trajectory comprised of a plurality of touch events triggered by an object approaching or physically touching the touch area.
From user's view point, touch traces imply the instructions one intends to do with the computer. The present invention focuses on the touch traces with their starting points falling outside of the touch area. Take the Windows 8 operating system for example, when the user's finger is detected as sliding in the touch area from the right edge of the touch panel or touch pad, a start menu slides off the right edge of the screen so the user can manipulate. The present invention focuses on such cases but as the people skilled in the art will understand, the present invention is not limited to Microsoft's Windows operating systems.
Saving power is another trend for today's consumer electronic products. After idling for a certain amount of time, components are either shut down or set to lower their operating frequencies in order to save energy. Referring to FIG. 1, which is a diagram illustrating a conventional electronic device 100. As shown, electronic device 100 comprises a central processor 110, a bridge 120, a graphical processor 130, a memory 140, a touch module 150, and a display module 160. The central processor 110 is configured for executing an operating system, such as the above mentioned Windows 8 or Android. The operating system monitors and controls all components of the electronic device 100. The display module 160 is electrically coupled with the graphical processor 130. The touch module 150 is electrically couple with the bridge 120. The memory 140 is electrically coupled with the central processor 110. The touch module 150 may be a touch panel which works with the display module 160, or a touch pad. The electronic device 100 may further comprise keyboard, mouse, hard drive and networking unit, etc. These components are neglected herein for simplicity.
When the operating system detects that the electronic device 100 has been idle for a while, it instructs individual component to take energy conservation actions. For example, the display module 160 may first dim to save power, and shut down the screen eventually. The graphical processor 130, which controls the display module 160, may lower its operating frequency, and even shut down completely following the display unit 160. The touch module 150 can also lower its scanning frequency first and the internal operating frequency of the circuits, and finally shut down completely. The operating system can instruct the central processor 110 to lower its operating frequency. In other words, for different power saving modes, individual component of the electronic device 100 can be set to different power saving work modes. As long as one single component is in its power saving mode, the overall power consumption of the electronic device 100 is reduced as compared to the normal work mode.
The electronic device 100 can restore from the power saving mode upon receipt of a trigger event. The trigger event may be a package sent from the network, or completion of a preset counter in the central processor 110. The most common trigger event that awakes the electronic device 100 is an input event triggered by the input unit(s), such as the keyboard, mouse, or the touch module 150.
Having to stand by for the user's input, the input units of the electronic device 100 restore from and then enter the hibernation mode periodically. For example, the user's touch action typically spans at least a tiny fraction of a second, therefore the touch module 150 can come back to normal work mode every dozens of milliseconds from hibernation mode and scan the touch area. If an input has taken place, the touch module 150 reports it to the bridge 120 and central processor 110, so that the operating system brings the entire electronic device 100 back to the normal work mode.
Referring to FIG. 2, which is a diagram illustrating working status of the touch module 150 in the power saving mode. In the upper half part (a) of FIG. 2, a scenario is illustrated where no touch action by the user are detected over the time span observed. As shown, to save power while keeping detecting for the user's inputs, the touch module 150 recovers to the work (detecting) mode from hibernation periodically, to detect whether there is an object approaching or physically touching the touch area. If no object is detected to be approaching or touching the touch area, the touch module 150 hibernates again, and so on.
In the lower half part (b) of FIG. 2, the user made a touch input action starting outside of the touch area, to both wake up the electronic device 100 and instruct it to execute the instructions suggested by such action (for example, in Windows 8, a start menu may slide off the edge of the screen as a response). In this touch action, the very first contact is made outside of the touch area of the touch module 150, at time T0 (not shown). The contact continues and enters the touch area at time T1. At this moment, the touch module 150 is still in hibernation and is unaware of the contact in the touch area. After the touch module 150 wakes up as scheduled, it detects touch contact at time T2. The detection of contact prevents the touch module 150 from hibernating again and keeps it in the work mode. As a result, another contact made by the same touch action is detected at time T3.
In certain circumstances, the location of contact detected at T2 may already be far away from the edge of the touch area. In such case, the touch module 150 will not consider the touch input action to be taking place outside of the touch area. The operating system will then associate the touch events of T2 and T3 into a touch trace which starts within the touch area, and responds accordingly. As a result, the user will not get responses he expected to see i.e. actions corresponding to the “intended” touch trace, which started outside of the touch area, but ones corresponding to a touch trace starting inside the touch area instead.
Therefore, a device and method is desired for correctly detecting a touch trace starting outside of the touch area under the power saving mode, so that the user can get the right responses.
From the above it is clear that prior art still has shortcomings. In order to solve these problems, efforts have long been made in vain, while ordinary products and methods offering no appropriate structures and methods. Thus, there is a need in the industry for a novel technique that solves these problems.